Broken shower head extension (soldered joint) - please help!

Well, shamefully my first post here is a plea for help. I searched for a solution but all I came up with was solutions to the problem of the shower head stem itself breaking off inside the copper nipple. That is not quite my problem (please see attached pictures).

In my case, there is actually a short (about 2.5" long) copper extension coming off the main copper water line. piece has broken free at the soldered joint. This happened when I was trying to remove the shower head from the stem to install a new shower head.

My question is this - is there any way to fix this without soldering? I don't imagine it is possible to solder behind the wall, and fear that I now have to rip my shower wall apart to fix the problem I've created